Sensor fault detection under asynchronous switched systems with state delays

This study aims to develop a technique for detecting sensor faults in continuous-time asynchronous switched time- delay systems using Mode Dependent Average Dwell Time (MDADT) switching. Introducing a sliding mode observer for fault detection aims to generate a residual signal. In complex asynchronous switched systems, the observer lags behind the corresponding subsystem or mode, resulting in matched and mismatched periods. Furthermore, the presence of time delays in asynchronous switched systems, such as delays between subsystems and observer lag time, and state delays, adds to the complexity of the problem. A Lyapunov function is chosen for matched and mismatched periods combined with MDADT to achieve global uniform asymptotic stability. By using the H∞ performance index, the presence of faults mitigates the influence of residual error signals. By establishing adequate conditions, linear matrix inequalities can be derived, and observer parameters and matrix parameters can be designed accordingly. In conclusion, an illustrative numerical example demonstrates the efficacy of the proposed technique.